Patent Literature 1: JP 2007-060158 A (US 2007/047948 A1)
There is conventionally known an in-vehicle driving support control system, which includes an image capturing apparatus to capture an image, and a control apparatus to perform a driving support control which assists travel of a vehicle based on the surrounding state of the vehicle detected from the image captured by the image capturing apparatus.
The driving support control includes an automatic wiper control, an adaptive cruise control, and a pre-crash safety control, for instance. The automatic wiper control captures an image of the windshield, detects raindrops based on the captured image, determines that the surrounding state of the vehicle is a state where it is raining, and actuates the wiper automatically. The adaptive cruise control captures an image of an area over the road the vehicle travels, detects a traveling-ahead vehicle based on the captured image, determines that the surrounding state of the vehicle is a state where a traveling-ahead vehicle is present, and controls the behavior of the vehicle to follow the traveling-ahead vehicle. The pre-crash safety control captures an image of an area over a road the vehicle travels, detects an object on the road based on the captured image, determines that the surrounding state of the vehicle is a state where a crash-unavoidable object is present, and applies a braking force to the vehicle or winds the seat belt up.
Such a driving support control system requires an image capturing apparatus which detects the surrounding state of the vehicle accurately to permit a single captured image (i.e., a picture) to represent simultaneously different objects having respective distances from the vehicle. The different objects having respective different distances from the vehicle exemplified by the windshield of the vehicle and a traveling-ahead vehicle or unavoidable object on the road the vehicle travels.
Patent Literature 1 proposes an image capturing apparatus (i.e., camera module) to achieve the above requirement. The image capturing apparatus includes a first lens having a specified first focal length, a second lens having a second focal length that is longer than the first focal length, an image sensor to focus incident light to generate a picture, a second mirror to reflect the light which passed through the second lens, and
a first mirror to reflect the light reflected by the second mirror such that the reflected light falls on the image sensor while transmitting the light having passed through the first mirror such that the transmitted light falls on the image sensor.
In general, vehicles are required to provide a larger space of occupant compartment or to secure the visibility in the heading direction; thus, the image capturing apparatus arranged in the occupant compartment is required to have a smaller size.
However, the image capturing apparatus in Patent Literature 1, which includes two lenses, two mirrors, and a image sensor, thus needs many components; this configuration is insufficient in making the size smaller.
That is, the image capturing apparatus in Patent Literature 1 does not enable at the same time (i) the generation of the captured image which clearly expresses simultaneously several objects having mutually different distances from the vehicle, and (ii) sufficient miniaturization of the image capturing apparatus itself.